The dual-action formula of Roundup Ready-To-Use Extended Control Weed & Grass Killer Plus Weed Preventer II with Comfort Wand kills existing weeds and prevents new ones from growing for up to four monthsâ€”and it kills them down to the root, guaranteed. Plus, the Weed & Grass Killer can be used on driveways, sidewalks, patios, along fences, curbs, retaining walls, and edges of lawns, as well as on decorative rock or gravel areas. Use the extendable Comfort Wand with continuous spray for more accuracy without bending over. Rainproof in 10 minutes with visible results in 3 hours, Roundup works. Fast.Customer Guarantee: If for any reason you are not satisfied after using this product, simply send us original proof of purchase, and we will refund the purchase price.